1/1  B  R.AFLY 

OF  THE 

UNIVERSITY 
OF    ILLINOIS 


G30.T 


co  p 


.  2. 


AGRICULTURE 


NON  CIRCULATING 

'  CHECK  FOR  UNBOUND 
CIRCULATING  COPY 


Agricultural  Experiment  Station 

UNIVERSITY  OF  ILLINOIS 


BULLETIN  NO.  295 


COSTS  OF  STORING  CORN 
ON  THE  FARM 

BY  LACEY  F.  RICKEY 


THBAXA,  ILLINOIS,  JUNE,  1927 


FOREWORD 

During  the  past  few  years  there  has  been  an  in- 
creasing need  for  information  with  regard  to  the  busi- 
ness aspects  of  farming,  including  the  problems  con- 
nected with  the  marketing  of  farm  products. 

With  the  approval  of  the  Purnell  Act  by  Congress 
in  February,  1925,  not  only  was  the  principle  estab- 
lished that  it  is  a  proper  and  legitimate  function  of  an 
Agricultural  Experiment  Station  to  make  inquiries 
and  investigations  into  the  social,  economic,  and  dis- 
tribution fields,  but  also  the  Stations  of  the  country 
had  placed  at  their  disposal  the  means  for  enlarging 
their  investigations  along  these  lines. 

While  the  Illinois  Station  has  long  recognized  the 
economic  problems  of  agriculture,  and  has  issued  many 
publications  having  to  do  with  them,  attention  is  called 
to  the  fact  that  this  bulletin  is  the  first  one  to  be 
issued  under  the  enlarged  program  made  possible  by 
the  Purnell  Act. 


Dean  and  Director 


COSTS  OF  STORING  CORN 
ON  THE  FARM 

By  LACEY  F.  RICKEY,  Associate  in  Grain  Marketing  Technology 

The  question  of  the  best  time  to  sell  corn  intended  for  market  is 
a  question  of  when  the  largest  net  amount  may  be  secured  for  the 
corn.  A  number  of  factors  must  be  considered  before  a  satisfactory 
answer  to  such  a  question  may  be  found.  These  are:  interest  on  the 
money  tied  up  in  the  corn,  interest  and  depreciation  charges  on  cribs 
used,  insurance  against  loss  from  fire  and  storms,  shrinkage,  and 
change  in  grade. 

It  is  not  within  the  province  of  this  circular  to  consider  price 
changes  that  may  occur  during  storage,  but  rather  to  discuss  the  costs 
which  are  incurred.  With  the  net  result  of  the  items  of  cost  and  of 
profit  in  mind,  the  farmer  is  in  a  position  to  consider  the  condition  of 
the  market  and  to  judge  whether  or  not  an  advance  sufficient  to  offset, 
or  to  more  than  offset,  the  amount  of  the  net  cost  may  reasonably  be 
expected  during  the  contemplated  storage  period.  He  may  then  deter- 
mine for  himself  the  best  time,  under  the  conditions  existing  on  his  own 
farm,  for  him  to  sell  corn. 

Interest  Charge  Always  a  Factor  in  Holding  Corn 

If  the  corn  is  sold  early,  interest  may  be  earned  on  the  money 
obtained  from  its  sale,  or  indebtedness  may  be  reduced  and  interest 
thus  saved.  In  any  case  the  interest  charge  will  be  directly  propor- 
tional to  the  rate  of  interest  and  the  length  of  the  storage  period,  so 
that  the  actual  charge  can  be  readily  computed  in  each  individual  case. 

With  corn  at  60  cents  a  bushel  and  interest  at  6  percent,  the 
charge  would  be  3.6  cents  a  bushel  a  year,  or  %0  cent  a  month.  Sim- 
ilar monthly  charges  can  be  readily  determined  to  correspond  with  the 
actual  early  winter  price  of  corn  and  the  local  rate  of  interest. 

Cost  of  Storage  Not  Usually  Affected  by  Crib  Costs 

If  the  holding  of  the  crop  necessitates  the  building  of  new  storage 
facilities,  the  cost  of  erecting  and  maintaining  the  cribs  must  be  con- 
sidered. In  most  cases,  however,  this  charge  for  cost  of  construction 
and  maintenance  should  not  be  added  to  the  cost  of  storage.  Corn  is 
seldom  hauled  direct  from  the  field  to  the  country  elevator  or  other 
point  of  sale,  and  provision  must  be  made  for  storage  from  the  time 
of  husking  until  the  corn  is  ready  to  shell  or  is  otherwise  disposed  of. 
Whether  the  cribs  are  in  use  one  month  or  ten  months  out  of  the  year 
makes  little  or  no  difference  in  the  cost  of  maintenance.  This  charge 


694992 


4  BVLLETIX  Xo.  295  [June, 

becomes,  therefore,  a  general  charge  against  the  corn  crop  rather  than 
against  its  storage  for  delayed  marketing. 

A  substantial,  permanent  crib  furnishes  the  most  economical  stor- 
age for  corn.  Wire  or  slat  pens  and  cheap  shed  cribs  are  less  expensive 
to  construct,  but  increased  losses  due  to  weather  and  vermin  may 
more  than  offset  this  saving.  A  good  substantial  crib  can  be  built  and 
maintained  at  an  annual  charge  of  about  3  cents  a  bushel  of  capacity. 
A  well-made  shed-type  crib  of  1,000  bushels  capacity  can  be  built  on 
this  basis.1  Increasing  the  size  decreases  the  cost  per  bushel  of  ca- 
pacity, so  that  a  large  double  crib  with  overhead  bins  and  complete 
unloading  and  elevating  equipment  can  be  built  and  maintained  on 
the  basis  of  an  annual  charge  of  3  cents  a  bushel  when  its  capacity 
can  be  fully  utilized. 

High  Charges  Make  Terminal  Storage  Inadvisable 

Storage  of  shelled  corn  at  the  terminal  markets  is  seldom  prac- 
tical for  farmers.  The  charges  at  Chicago  are  1%  cents  a  bushel  for 
unloading  and  elevating,  and  storage  for  the  first  ten  days.  Thereafter 
the  charge  is  %0  of  a  cent  a  day,  or  approximately  1%  cents  a  month. 
The  corn  is  mixed  with  other  corn  of  the  same  grade  and  when  de- 
livery is  asked  for,  the  same  number  of  pounds  of  the  same  grade  of 
corn  that  went  into  storage  is  delivered  to  the  owner.  Shrinkage  and 
change  in  grade  therefore  do  not  enter  into  the  problem  when  corn  is 
stored  in  public  elevators  at  the  terminal  markets.  High-moisture  corn 
will  not  be  accepted  for  storage,  and  in  case  the  grain  starts  to  go  out 
of  condition,  the  elevator  has  the  right  to  order  it  removed. 

Charges  for  terminal  storage  exceed  considerably  the  cost  of  farm 
storage,  but  there  is  one  advantage,  that  if  there  is  a  favorable 
'"bulge"  in  the  market  the  corn  may  be  sold  on  a  moment's  notice.  Of 
course  the  owner  must  be  in  close  touch  with  the  market  in  order  to 
know  when  such  conditions  occur. 

Insurance  Charges  About  1/10  Cent  a  Month  a  Bushel 

The  expense  of  insuring  the  corn  while  it  is  in  farm  storage  should 
be  added  to  the  other  items  of  cost.  The  risk  is  there  no  matter 
whether  it  is  carried  by  the  owner  or  turned  over  to  an  insurance  com- 
pany; therefore  it  is  correct  to  add  this  charge  under  all  conditions. 
Insurance  rates  vary  considerably  according  to  the  type  of  company 
writing  the  policy,  the  risks  insured  against,  and  the  general  type  of 
the  policy.  The  average  charge  for  protection  against  fire,  lightning, 
and  tornado  is  about  %0  of  a  cent  a  month  for  each  bushel. 


'Information  on  the  construction  of  cribs  may  be  obtained  on  request  from 
the  Farm  Mechanics  Department  of  this  Station. 


1927 } 


COSTS  OF  STOKING  CORN 


Shrinkage  and  Change  in  Grade  Important  Considerations 

The  question  of  the  amount  of  shrinkage  which  occurs  under  vari- 
ous conditions  is  best  determined  from  carefully  conducted  experi- 
ments. The  results  of  extensive  shrinkage  tests  on  ear  corn  made  at 
this  Station  from  1903  to  1913  are  given  in  Table  I.1 

Losses  due  to  shrinkage  vary  with  the  method  used  in  selling  the 
corn,  whether  on  the  ear  without  considering  the  grade,  on  the  ear  ac- 
cording to  grade,  or  on  a  shelled  basis.  Since  gains  or  losses  due  to 


TABLE  1.  —SHRINKAGE  OF  EAR  CORN  BY  MONTHS  FOR  THE  YEARS  1903- 

19131  AT  URBANA,  ILLINOIS 

(Expressed  in  percentage) 


Month 

1903 

1905 

1906 

1907 

1909 

1910 

1911 

1912 

1913 

Average 
for  9 
years 

Monthly 
average 

Nov  

.8 

2.5 

1.1 

(-.1) 

1.8 

1.9 

1.3 

Dec. 

3.2 

5  5 

2  8 

2  2 

4  5 

1  2 

5  0 

1  7 

3  3 

1  9 

4  5 

6  7 

3  3 

4  5 

4  8 

2  7 

6  8 

3  0 

1   1 

4.2 

9 

Feb  

5.6 

8  6 

4  9 

6  3 

6  5 

3  8 

7  5 

3  9 

2  3 

5  5 

1  3 

Mar  

6.9 

8.5 

7  3 

9  4 

9  2 

6  9 

7  6 

5  0 

1.9 

7.0 

1  5 

Apr  

11.1 

10.0 

10.5 

12.4 

13  5 

8.7 

11  4 

7.2 

5.1 

10.0 

3.0 

May  

15.4 

13.6 

11.9 

13.8 

13.7 

12.4 

17.1 

11.2 

8.9 

13.1 

3.  1 

June  

17.9 

14.2 

13.2 

16.8 

15.7 

15.1 

20.3 

13.2 

11.3 

15.3 

2.2 

July  

19.0 
20  2 

15.3 
15  1 

14.1 
14  8 

18.0 
19  0 

15.7 
15  6 

16.8 
16  9 

20.3 
21   1 

13.6 
13  5 

12.5 
13  3 

16.2 
16  6 

.9 
5 

Sept.   . 

19  8 

15  2 

15  2 

20  1 

14  8 

15  4 

21  3 

13  7 

12  1 

16  4 

(-  2) 

Oct  

19.8 

15.5 

20.6 

14.9 

14.7 

21.6 

12.2 

13.0 

16.5 

.2 

Nov  

19  9 

15.1 

20  2 

15  4 

14  7 

21  6 

11  2 

12  4 

16.3 

(-.2) 

Dec  

10.1 

'With  the  exception  of  1904  and  1908,  for  which  data  are  unavailable. 

(From  Bulletin  183,  "Prices  and  Shrinkage  of  Farm  Grains,"  111.  Agr.  Exp.  Sta.,  1915.) 


changes  in  grade  are  also  affected  by  the  same  sets  of  conditions  as 
those  due  to  shrinkage,  the  question  of  change  in  grade  will  be  consid- 
ered along  with  that  of  shrinkage. 

Corn  Sold  on  the  Ear,  Grade  Not  Considered 

When  ear  corn  is  sold  simply  as  "corn"  without  any  specific  dif- 
ference being  made  in  the  price  for  different  grades,  the  sale  is  usually 


'In  1924  special  equipment  was  .set  up  in  order  to  obtain  further  information 
on  this  question.  This  equipment  consists  of  eight  cribs,  each  having  a  capacity 
of  about  300  bushels  of  ear  corn,  which  are  mounted  on  wheels  and  run  on  a 
short  track.  At  the  center  of  this  track  is  a  scale.  Each  week  the  cribs  are  drawn 
across  the  scale  and  weighed.  The  sides  of  cribs  are  boarded  up  tight  when 
studies  are  being  made  on  small  grains. 

Equipment  is  also  provided  for  blowing  either  cold  or  heated  air  thru  the 
cribs  in  order  to  determine  practical  methods  for  drying  different  crops  under 
various  conditions.  The  results  thus  far  secured  substantiate  the  conclusions 
drawn  from  the  earlier  experiments  in  regard  to  the  rate  of  shrinkage  of  ear  corn. 
Data  concerning  the  best  methods  of  handling  soft  corn,  the  effect  of  methods  of 
drying  on  the  germinating  power  of  corn,  and  the  changing  relationship  between 
the  percentage  of  moisture  in  the  cobs  and  in  the  kernels,  are  also  being  secured. 


6  BVLI.KTIN  No.  295  [June, 

made  either  by  one  farmer  to  another  or,  in  sections  where  farm  corn 
shellers  are  not  common,  by  the  farmer  to  other  purchasers.  A  fact  to 
be  considered  in  this  type  of  sale  is  that  the  70  pounds  of  well-cured 
ear  corn  usually  accepted  as  the  bushel  will  actually  shell  out  more 
than  56  pounds  of  shelled  corn.  The  overrun  will  usually  be  between  3 
and  5  percent,  and  it  is  customary  to  consider  that  this  is  sufficient  at 
least  to  pay  the  cost  of  shelling. 

The  question  of  shrinkage  when  sales  are  made  in  this  manner  is 
clearly  only  one  of  loss  in  weight  of  the  ear  corn.  Of  tests  made  at 
different  experiment  stations  to  determine  the  amount  of  this  loss  in 
weight,  those  made  at  the  Illinois  Station  from  1903  to  1913  seem  to 
have  been  the  most  complete.  Quoting  from  Bulletin  183,  "Prices 
and  Shrinkage  of  Farm  Grains"  (1915) :  "Each  year  about  300  bushels 
of  corn  were  hauled  direct  from  the  field  and  placed  in  an  open  crib, 
protected  by  tight  roof  and  by  slat  sides,  where  it  was  left  until  the 
next  crop  was  gathered.  Four  times  each  month  the  crib  and  its  con- 
tents were  weighed  to  determine  the  shrinkage.  The  average  of  the 
four  weighings  was  taken  as  the  monthly  average  from  which  to  com- 
pute the  shrinkage  of  the  corn.  In  these  experiments  the  months  of 
maximum  shrinkage  were  found  to  be  April,  May,  and  June.  After 
January,  there  was  a  gradual  increase  in  the  shrinkage  rate  until  May, 
and  from  that  point  on,  there  was  a  decided  decrease.  The  corn 
reached  its  minimum  weight  in  August." 

The  corn  used,  which  represented  a  good  average  of  the  crop  as  it 
went  into  farmers'  cribs  in  central  Illinois  during  each  particular 
year,  was  weighed  both  into  and  out  of  the  crib  at  70  pounds  to  the 
bushel.  Corn  often  is  bought  during  the  early  winter  on  the  basis  of 
75  pounds  to  the  bushel,  which  amounts  to  taking  an  allowance  of 
about  6.7  percent  for  shrinkage.  Thus,  so  far  as  shrinkage  is  concerned, 
approximately  the  same  amount  would  have  been  secured  by  selling 
in  March  at  70  pounds  a  bushel  as  would  have  been  obtained  by  selling 
in  November  at  75  pounds  a  bushel. 

The  methods  now  employed  for  determining  the  percentage  of 
moisture  in  corn  were  not  in  common  use  at  the  time  of  the  early  ex- 
periments reported  in  Bulletin  183,  and  no  information  is  available  as 
to  the  moisture  contained  in  this  corn.  It  will  be  noticed,  however. 
that  there  is  considerable  difference  in  the  shrinkage  in  various  years. 
undoubtedly  due  largely  to  differences  in  the  moisture  content  of  the 
corn  when  it  was  placed  in  the  crib. 

It  may  be  safely  assumed  that  in  years  when  corn  is  well  matured 
and  comparatively  dry  when  husked,  the  shrinkage  from  November 
until  the  following  summer  will  be  around  14  or  15  percent.  On  the 
other  hand,  when  corn  goes  into  the  crib  in  a  rather  sappy  condition, 
the  shrinkage  will  amount  to  18  or  20  percent  or  even  more. 


1927]  COSTS  OK  STORING  COK.N  7 

Instead  of  using  the  average,  therefore,  in  applying  these  results, 
it  is  better  to  select  from  the  table  some  year  for  which  the  figures  ap- 
pear to  fit  the  conditions  of  the  year  under  consideration.  For  in- 
stance, when  corn  is  cribbed  late  in  the  season  in  a  year  when  it  is 
well  matured  and  has  had  a  good  chance  to  dry  in  the  field,  the  prob- 
able shrinkage  is  best  indicated  by  that  determined  for  the  year  1913 
or  1906,  when  the  loss  in  weight  was  comparatively  small.  On  the 
other  hand,  if  conditions  have  made  necessary  the  cribbing  of  corn 
containing  considerable  moisture,  the  larger  shrinkage  given  for  1911 
or  1903  will  more  closely  indicate  the  loss  in  weight  to  be  expected. 

In  selling  corn  on  this  basis,  without  considering  definitely  the 
grade  of  the  grain,  any  raising  of  the  grade  thru  storage  benefits  the 
seller  only  in  a  general  way.  and  no  definite  value  can  be  assigned  to 
it. 

Corn  Sold  on  the  Ear,  Grade  Considered 

A  different  set  of  conditions  is  encountered  when  the  corn  is  sold 
as  ear  corn  but  on  the  basis  of  grades  determined  after  the  corn  is 
shelled.  Such  conditions  obtain  where  corn  is  sold  on  the  ear  to  coun- 
try elevators  to  be  shelled  at  the  elevator. 

The  situation  here  in  regard  to  shrinkage  is  the  same  as  in  the 
preceding  section  except  that  change  in  grade  becomes  a  factor.  Corn 
sold  in  the  early  winter  months  usually  grades  No.  4  or  lower.  In 
fact,  very  large  amounts  of  the  1925  and  1926  crops  graded  No.  6,  or 
sample  grade,  early  in  the  season  merely  on  account  of  the  large 
amount  of  moisture.  When  properly  stored  and  allowed  to  dry  out, 
this  same  corn  during  the  following  summer  will  grade  No.  2  or  No.  3 
because  the  shrinkage  which  takes  place  is  accompanied  by,  and  is  in 
fact  largely  due  to,  a  loss  in  moisture. 

In  order  to  arrive  at  the  true  cost  of  storage  for  corn  sold  on  the 
ear  by  grade,  that  part  of  the  discount  demanded  by  the  market  on 
the  lower  grades,  which  may  be  avoided  by  holding  the  corn  over, 
should  be  deducted  from  the  costs  of  storing  the  grain.  Avoiding  the 
discount  amounts  to  the  same  thing  as  receiving  a  premium  for  hold- 
ing the  corn  during  the  time  that  its  grade  is  being  improved. 

The  discounts  taken  on  the  market  vary  from  time  to  time  ac- 
cording to  the  amount  of  low-grade  corn  which  is  coming  forward.  A 
small  amount  of  such  lower  grading  corn  can  be  used  to  fairly  good 
advantage,  but  as  the  proportion  grows  larger,  it  is  more  heavily  dis- 
criminated against.  The  discounts  can  be  determined  from  the  current 
market  reports.  As  a  general  rule,  with  cash  corn  selling  at  from  70 
to  90  cents  the  discounts  will  average  about  2  cents  to  a  grade,  or  1 
cent  for  each  additional  percentage  of  moisture  contained  in  the  corn. 
They  are  more  likely  to  run  over  this  figure  than  to  be  less,  especially 
early  in  the  season  in  years  when  the  crop  contains  more  moisture 


8  BULLETIN  No.  295  [June, 

than  usual.  No.  6  corn  may  sell  15  cents  or  more  under  No.  2,  rather 
than  8  cents  under,  as  indicated  above.  The  only  way  to  figure  the 
discounts  at  any  certain  time  is  to  notice  the  difference  in  the  market 
price  between  the  different  grades  of  cash  corn. 

The  requirements  for  the  different  grades  of  corn  under  the 
standards  set  up  by  the  U.  S.  Department  of  Agriculture  are  shown 
in  Table  2.  All  cars  of  corn  going  to  or  thru  terminal  market  points 
are  sampled  and  graded  according  to  these  requirements  by  licensed 
inspectors  who  are  under  the  supervision  of  the  Office  of  Federal  Grain 
Supervision. 

If  corn  is  properly  stored,  it  will  dry  down  to  about  13  percent 
of  moisture  by  early  summer.  So  far  as  moisture  is  concerned,  this 
would  allow  the  corn  to  grade  No.  1,  but  since  there  is  very  apt  to  be 
enough  damage  due  to  mold  or  other  causes,  enough  foreign  material 
and  cracked  corn,  or  a  large  enough  deficiency  in  weight  per  bushel 
to  bring  the  grade  down  to  No.  2  or  3,  it  is  better  to  expect  one  of  these 
grades  than  it  is  to  expect  the  corn  to  grade  No.  1. 

Corn  Sold  on  a  Shelled  Basis 

In  sections  where  large  amounts  of  corn  are  shipped  out,  a  third 
set  of  conditions  prevails.  The  grain  is  stored  as  ear  corn  but  is  shelled 
on  the  farm  or  at  the  elevator  at  the  time  of  delivery,  and  sold  on  a 
shelled  basis.  Under  this  practice,  which  is  common  thruout  a  large 
part  of  Illinois,  the  farmer  is  not  concerned  at  all  with  how  much  the 
cobs  shrink,  since  they  do  not  enter  into  the  sale  of  the  corn.  His  re- 
ceipts are  affected  only  by  that  part  of  the  shrinkage  which  is  due  to 
a  decrease  in  weight  in  the  kernels  themselves. 

The  determination  of  the  shrinkage  under  these  conditions  is  not 
so  simple  as  it  may  at  first  appear.  Taking  80  percent  of  the  total 
shrinkage  because  the  56  pounds  required  for  a  bushel  of  shelled  corn 
is  80  percent  of  the  70  pounds  required  for  a  bushel  on  the  ear,  does 
not  solve  the  problem.  It  would  if  the  cobs  and  the  kernels  contained 
the  same  percentage  of  moisture,  but  when  corn  is  cribbed  in  the  fall, 
the  cobs  contain  a  considerably  larger  percentage  of  moisture  than 
the  kernels.  When  taken  out  the  ..following  summer,  the  cobs  will  usu- 
ally contain  a  smaller  percentage  of  moisture  than  the  kernels.  A 
larger  proportion  of  the  total  shrinkage  is  therefore  due  to  loss  of 
moisture  from  the  cobs  than  to  loss  of  moisture  from  the  kernels 
themselves.  Experiments  to  discover  the  exact  relationship  between 
the  amount  of  moisture  in  the  cobs  and  that  in  the  kernels  under  the 
different  conditions  of  storage  are  being  carried  on  at  this  Station. 

Altho  exact  experimental  evidence  on  this  point  is  not  now  avail- 
able, the  shrinkage  of  corn  which  is  to  be  sold  on  a  shelled  basis  may 
be  estimated  with  a  reasonable  degree  of  accuracy.  Since  a  large  part 
of  the  shrinkage  is  due  to  the  loss  of  moisture,  the  difference  in  mois- 


19&  1 


('OSTS  OF  STORING  CORN 


9 


ture  content  when  the  corn  goes  into  storage  in  the  fall  and  when  it  is 
taken  out  the  following  spring  or  summer  is  a  good  index  of  the 
amount  of  shrinkage.  When  the  summer  months  arrive,  corn  will  have 
dried  down  to  about  13  percent  of  moisture  on  the  average,  irrespective 
of  whether  it  contained  18  percent  or  30  percent  when  it  was  placed 
in  the  crib. 

TABLE  2. — GRADE  REQUIREMENTS  FOR  WHITE,  YELE.OW,  AXD  MIXED 

SHELLED  CORN 
(I*.  S.  Department  of  Agriculture  Standards) 


Grade  Xo. 

Minimum 
test 
weight 
per 
bushel 

Maximum  limits  of  — 

Mois- 
ture 

Foreign 
material 
and 
cracked 
corn 

Damaged  corn 

Total 

Heat 
damage 

1.  . 

Ibs. 
55 
53 
51 
49 
47 
44 

perct. 

14.0 
15.5 
17.5 
19.5 
21.5 
23.0 

perct. 
2 
3 
4 
5 
6 
7 

perct. 

2 
4 
6 
8 
10 
15 

perct. 
0.0 
.1 
.3 
.5 
1.0 
3.0 

2  

3  

4    .  . 

5  

61  

Sample  grade. . . 


White  corn,  or  yellow  corn,  or  mixed  corn,  respectively,  which 
does  not  come  within  the  requirements  of  any  of  the  grades  from 
Xo.  1  to  Xo.  (i  inclusive,  or  which  has  any  commercially  objec- 
tionable foreign  odor,  or  is  heating,  hot,  infested  with  live 
weevils  or  other  insects  injurious  to  stored  grain,  or  is  otherwise 
of  distinctly  low  quality.  


'The  corn  in  grades  Nos.  1  to  5  inclusive  shall  be  cool  and  sweet.     The  corn  in 
grade  No.  6  shall  be  cool  but  may  be  musty  or  sour. 

How  is  the  farmer  to  know  the  percentage  of  moisture  contained 
in  his  corn  when  it  goes  into  storage? 

Most  country  elevators  have  equipment  for  making  this  test  and 
will  gladly  do  so  for  their  patrons.  It  is  very  important  that  the 
sample  used  for  determining  moisture  be  representative  of  the  entire 
lot  of  corn.  In  collecting  such  a  sample  do  not  take  ears  from  the  top 
of  the  crib,  but  dig  clown  a  couple  of  feet  in  two  or  three  places  and 
obtain  a  dozen  or  more  average  ears  in  this  way.  Shell  at  once  and 
place  the  grain  in  mason  jars  or  other  air-tight  containers.  Thoroly 
mix  this  sample  before  taking  the  handful  used  for  the  test, 

A  rough  approximation  of  the  percentage  of  moisture  can  be  made 
by  weighing  the  sample  of  shelled  corn  and  placing  it  in  pans  on  a  shelf 
above  the  kitchen  stove  or  in  a  warm  place  near  the  furnace  for  several 
days.  Weigh  it  each  day,  and  when  the  grain  ceases  to  lose  weight  you 
can  be  assured  that  it  contains  not  more  than  2  or  3  percent  of  mois- 
ture. The  original  weight  divided  into  the  loss  in  weight  will  then 
give  approximately  the  percentage  of  moisture  originally  contained  in 
the  corn. 


10  BULLETIN-  No.  295  [June, 

Since  corn  left  to  dry  naturally  will  usually  retain  about  13 
percent  of  moisture,  even  during  the  hot  summer  months,  and  since  we 
have  assumed  that  2  or  3  percent  of  moisture  remains  in  the  corn  when 
dried  in  the  artificial  manner  described  above,  10  or  11  should  be  sub- 
tracted from  the  percentage  thus  determined  in  order  to  find  what  the 
loss  of  moisture  will  be  from  corn  held  in  the  crib. 


NO.  3  ;   NO.  4      NO,  S    - 140,  S  ^  k 

t7&:%  IjI&°X      '     .  %     H3%.  ij 

•>OV 

I;  23 


FIG.  1. — AMOUNT  OF  WATER  CONTAINED  IN  A  BUSHEL  OF  SHELLED  CORN 
This  series  of  2-gallon  bottles  shows  the  maximum  amount  of  water  con- 
tained in  a  bushel  of  corn  of  the  different  grades.  The  foot-rule  and  12-quart 
bucket  enable  one  to  visualize  the  quantities.  No.  1  corn  may  contain  up  to 
15/16  of  a  gallon  of  water.  Corn  which  grades  "sample"  on  account  of  moisture 
contains  more  than  1%  gallons  of  water  a  bushel.  In  very  soft  corn  this  amount 
would  be  as  much  as  3  gallons. 

A  loss  of  say  17  percent  of  moisture  means,  however,  a  loss  of 
more  than  this  percentage  in  weight,  because  the  base  of  calculation 
is  changed.  Reducing  the  moisture  content  from  30  percent  to  13  per- 
cent actually  results  in  a  loss  in  weight  of  19.5  percent.1 

However,  there  is  still  another  item  of  shrinkage.  During  the 
period  of  storage  there  are  chemical  changes  going  on  in  the  corn  by 
which  some  of  the  solid  matter  is  converted  into  water  and  gases  which 
pass  off  into  the  air.  A  small  amount  of  the  volatile  oils  in  the  corn  is 
also  lost  in  this  way.  These  losses  are  not  so  very  large,  but  consider- 
able experimental  work  must  be  done  before  they  can  be  determined 
accurately.  Adding  10  percent  of  the  amount  of  shrinkage  which  has 
been  determined  from  the  change  in  moisture  content  will  probably  be 
ample  to  take  care  of  this  additional  loss. 

lThis  may  be  demonstrated  as  follows:  100  pounds  of  corn  containing  30 
percent  (pounds)  of  moisture  will  contain  70  pounds  of  dry  matter.  By  drying 
this  corn  until  it  contains  only  13  percent  of  moisture,  the  amount  of  dry  matter 
will  not  be  changed.  There  will  still  be  70  pounds  of  it.  This  70  pounds,  however, 
now  represents  87  percent  (100  minus  13)  of  the  total  remaining  weight.  The 
total  weight  of  the  dried  corn  is  therefore  found  by  dividing  70  by  87  and  mul- 
tiplying by  100,  which  gives  80.5  pounds.  Since  it  weighed  100  pounds  before  dry- 
ing, the  shrinkage  has  been  19.5  pounds,  or  19.5  percent. 


1927] 


COSTS  OF  STORING  CORN 


11 


TABLE  3. — SHRINKAGE  OF  SHELLED  CORN 

If  enough  ear  corn  to  shell  out  1,000  bushels  is  placed  in  cribs  when  it  contains 
the  percentage  of  moisture  shown  in  the  left  column  of  this  table,  and  is  allowed  to 
dry  down  to  a  moisture  content  corresponding  to  that  shown  at  the  tops  of  the  other 
columns,  the  number  of  bushels  of  shelled  corn  which  will  remain  is  shown  in  the  body 
of  the  table. 


Moisture  in 
corn  when 
cribbed 

Grade,  if 
moisture  is 
limiting  factor 

Amount  of  shelled  corn  remaining  at  end 
of  storage  period  when  moisture  content  is  — 

12% 

13% 

14% 

15% 

16% 

17% 

perct. 
32 
30 
28 
26 
24 
23 
21.5 
19.5 

Sample  

bu. 
750 

775 
799 
825 
850 
862 
881 
906 

bu. 
760 
785 
810 
836 
861 
873 
892 
918 

bu. 
770 
795 
821 
847 
872 
885 
904 
930 

bu. 
780 
806 
832 
858 
884 
896 
916 
942 

bu. 
790 
817 
843 
869 
895 
908 
928 
954 

bu. 
801 
828 
854 
881 
907 
920 
940 
967 

Sample  

Sample  

Sample  

Sample  

6  

5           

4  

NOTE  1. — The  above  results  are  obtained  by  dividing  the  percentage  of  dry 
matter  in  the  corn  at  the  beginning  of  storage  (100  minus  original  percentage  of 
moisture)  by  the  percentage  of  dry  matter  remaining  at  the  end  of  the  storage 
period  (100  minus  final  percentage  of  moisture)  and  multiplying  by  1,000.  The  loss 
thus  determined  has  been  arbitrarily  increased  by  one-tenth  to  cover  unaccounted 
losses. 

NOTE  2. — Corn  containing  30  percent  or  more  of  moisture  would  usually  be  con- 
sidered "soft." 

When  all  the  above  factors  are  taken  into  consideration,  the  total 
shrinkage  will  be  such  as  to  leave  at  the  end  of  the  storage  period  the 
amount  of  corn  indicated  in  Table  3.  In  general,  the  percentage  of 
shrinkage  on  a  shelled  basis  will  range  between  two-thirds  and  three- 
fourths  as  much  as  will  the  percentage  of  shrinkage  for  ear  corn  as 
given  in  Table  1. 

Figuring  Storage  Costs 

Example  1 :  When  Corn  Is  Sold  on  the  Ear  at  70 
Pounds  to  the  Bushel 

When  corn  is  sold  on  the  ear,  the  price  increase  necessary  to  off- 
set the  costs  of  carrying  the  corn  for  delayed  marketing  may  be  de- 
termined as  follows: 

Let  us  assume  that  new  corn  is  selling  in  November  for  60  cents 
a  bushel  of  70  pounds  in  a  year  when  the  moisture  content  of  corn  is 
fairly  high.  By  referring  to  Table  1  it  is  decided  that  conditions  cor- 
respond to  those  of  1903.  What  price  must  be  obtained  the  following 
June  to  offset  the  costs  incurred?  The  shrinkage  up  until  June  will 
amount  to  17.9  percent,  or  let  us  say  18  percent.  Subtracting  this 
figure  from  100  leaves  82,  which  divided  into  the  60  cents  obtainable 
at  husking  time  gives  the  price  which  will  offset  the  shrinkage.  To 
this  result  must  be  added  the  cost  of  interest  and  insurance,  and  the 


12  BULLETIN  No.  295  [June, 

charge  for  the  use  of  crib  if  conditions  are  such  that  this  item  should 
be  included. 

100%  —  18%  =  82%  60  -4-  82  =  .732 

100  times  .732  cents  =  73.2  cents 

Interest  at  6%  for  7  months =    2.1  cents 

Insurance  for  7  months =      .7  cents 


Total 76.0  cent  < 

Under  these  conditions  then,  76  cents  in  June  amounts  to  60  cents 
in  the  preceding  November. 

Example  2:  When  Corn  Is  Sold  on  the  Ear  at 
75  Pounds  to  the  Bushel 

If  75  pounds  must  be  given  for  a  bushel  in  November,  however, 
the  increase  in  price  required  to  offset  storage  charges  need  not  be  so 
large.  Let  us  figure  on  the  basis  of  100  bushels,  or  7,000  pounds  of  ear 
corn  at  husking  time. 

Since  75  pounds  are  to  be  given  for  a  bushel,  this  is  equal  to  only 
93%  bushels.  If  the  corn  is  held  over  and  the  shrinkage  amounts  to  18 
percent  (see  Example  1),  82  bushels  of  70  pounds  each  will  be  left  for 
sale  the  following  summer.  This  represents  a  loss  of  11%  bushels  as 
compared  with  the  fall  sale,  or  12.1  percent  on  the  basis  of  93%  bush- 
els. We  have  then — 

100%  —  12.1%  =  87.9%  60  -r-  87.9  =  .683 

100  times  .683  cents  =  68.3  cents 

Interest  at  6%  for  7  months =    2.1  cents 

Insurance  for  7  months..  ..  =      .7  cents 


Total 71.1  cents 

Example  3:  When  Ear  Corn  Is  Sold  According  to  Grade 

In  this  case  the  costs  of  holding  will  be  the  same  as  for  corn 
which  is  sold  without  reference  to  grade,  except  that  the  change  in 
grade  which  usually  occurs  during  storage  will  bring  a  return  which 
offsets  part  of  these  costs. 

Corn  of  rather  high  moisture  content  may  be  taken  to  illustrate 
this  case,  corn  which  would  grade  No.  6,  let  us  say.  If  it  is  sound 
corn  and  properly  dried  out,  it  should  grade  No.  2  the  following  sum- 
mer. This  change  in  grade  can  be  depended  upon  to  increase  the  price 
8  cents  or  more,  bringing  it  up  at  least  to  68  cents.  In  order  then  for 
the  June  price  for  this  corn  to  be  76  cents  or  71  cents  as  determined  in 
Examples  1  and  2  respectively,  it  will  be  necessary  for  the  general 
corn  market  to  rise  only  8  cents  if  70  pounds  are  given  for  a  bushel  in 
November  or  3  cents  if  75  pounds  must  be  given.  The  8  cents  which 
comes  from  the  bettering  of  the  grade  makes  up  the  rest  of  the  differ- 
ence between  November  and  June  prices. 


COSTS  OF  STORING  Coux  13 

Example  4'  When  Corn  Is  Sold  on  the  Shelled  Basis 
When  corn  is  shelled  before  being  sold,  the  moisture  content  must 
first  be  determined  as  nearly  as  possible.  By  mid-summer  the  corn 
will  usually  have  dried  down  to  about  13  percent  moisture.  If  the 
weather  is  very  dry,  it  may  go  down  to  12  or  even  11  percent  under 
Illinois  conditions.  The  number  of  bushels  of  shelled  corn  for  every 
1,000  bushels  cribbed  which  will  be  left  after  the  moisture  content  has 
been  reduced  during  storage  is  given  in  Table  3. 

Corn  containing  24  percent  of  moisture,  or  just  enough  to  force  it 
down  to  sample  grade,  will  be  taken  as  an  example.  'If  1,000  bushels 
of  this  corn  are  dried  down  to  13  percent  moisture,  861  bushels  will  be 
left,  according  to  Table  3.  We  may  assume  that  the  local  quotation 
for  corn  is  60  cents  in  November.  This  price  is  nearly  always  based  on 
No.  4  corn,  which  is  the  lowest  grade  deliverable  on  future  contracts.1 
The  market  discount  for  sample  grade,  under  the  price  for  No.  4, 
will  be  at  least  6  cents  and  may  run  up  to  as  much  as  15  cents.  Under 
normal  winter  market  conditions  this  corn,  containing  24  percent 
moisture,  would  have  to  take  a  discount  of  about  8  cents,  which  means 
a  net  price  of  52  cents.  The  1,000  bushels  would  then  sell  for  $520.  In 
order  to  receive  the  same  amount  for  the  861  bushels  which  the  corn 
will  weigh  out  after  it  shrinks,  the  price  must  be  60.4  cents.  Interest 
and  insurance  charges  should  be  added. 

$520.00-=-  861  =  60.4  cents 

Interest  at  6%  for  7  months =   2.1  cents 

Insurance  for  7  months..  ..=      .7  cents 


Total 63. 2  cents 

The  price  of  60  cents  offered  in  the  winter  was  based  on  No.  4 
corn.  By  summer  this  corn  should  grade  No.  2  or  No.  3  and  hence 
bring  from  2  to  5  cents  more  than  No.  4  corn.  If  No.  4  corn  is  still 
quoted  at  60  cents,  No.  3  should  sell  for  about  62  cents  and  No.  2 
for  about  64  or  65  cents.  It  appears  then  that  the  price  will  be  high 
enough,  with  no  change  in  the  market,  to  offset  the  cost  of  carrying 
this  corn. 

Or  let  it  be  assumed  that  the  corn  is  very  good  in  the  fall;  that 
it  contains  only  19.5  percent  of  moisture  and  grades  therefore  No.  4. 
When  1,000  bushels  of  this  corn  dries  down  to  13  percent  moisture, 
918  bushels  will  remain.  Using  the  same  prices  as  above,  $600  would 
be  received  for  this  corn  in  November,  and  to  obtain  as  large  a  total 


*In  January,  1927,  members  of  the  Chicago  Board  of  Trade  voted  to  amend 
their  rules  so  that  only  Nos.  1,  2,  and  3  corn  should  be  deliverable  on  future  con- 
tracts after  the  current  season.  Hereafter  it  is  probable  that  quotations  will  be 
made  on  the  basis  of  No.  3  corn. 


14  BULLETIN  No.  295  [June, 

the  following  summer,  a  price  of  65.4  cents  a  bushel  would  be  neces- 
sary. But  this  good  corn  should  then  grade  No.  2  or  possibly  No.  1, 
and  again  the  premium  over  No.  4  corn,  on  which  our  price  was  based, 
would  about  make  up  this  difference.  Any  increase  in  the  market  will 
turn  a  profit  to  the  owner  of  the  corn.  The  shrinkage  bugaboo  all  but 
disappears  when  considered  in  this  light. 

Damage  in  the  Cribs  May  Force  Corn  Into  the  Lower  Grades 

Other  factors  which  must  be  considered  in  deciding  how  long 
corn  should  be  stored  include  loss  from  rats,  fluctuations  in  the  cost  or 
convenience  of  shelling  and  hauling  the  corn,  and  the  possibility  of 
damage  to  the  corn  while  in  the  cribs.  In  a  good  substantial  crib  with 
concrete  floors  the  loss  from  rats  and  other  pests  will  be  very  small. 
If  poorer  construction  is  used,  this  loss  will  become  large  enough  to 
demand  attention  and  should  be  allowed  for  in  deciding  the  question  of 
holding  corn.  Fortunately  the  Illinois  farmer  need  not  expect  that 
insect  pests  will  cause  any  extensive  damage  to  corn  in  the  crib. 

The  cost  of  shelling  and  hauling  the  corn  also  has  a  seasonal 
aspect.  If  these  operations  should  be  allowed  to  interfere  with  field 
work  during  the  summer,  the  actual  cost  would  be  unreasonably  high. 
The  extent  to  which  this  must  be  considered  will  be  determined  by 
conditions  on  the  individual  farm.  Condition  of  the  country  roads 
also  must  often  be  taken  into  account  in  deciding  when  the  corn  is  to 
be  hauled. 

Probably  the  most  important  of  these  additional  factors  is  the 
possibility  of  damage  to  the  corn  while  in  the  cribs.  It  must  be  re- 
membered that  high  moisture  is  not  the  only  condition  that  forces  corn 
into  the  lower  grades.  If  the  corn  becomes  moldy  or  damaged  in  any 
other  way  to  an  appreciable  extent  during  storage,  this  fact  will  hold 
it  in  the  lower  grades  even  tho  the  moisture  content  has  been  reduced. 
In  this  case  the  shrinkage  loss  is  incurred  with  no  offsetting  advantage 
thru  bettering  the  grade.  The  data  in  Table  2  show  how  grades  are 
affected  by  these  conditions. 

In  holding  corn,  then,  one  must  be  sure  that  it  will  remain  cool 
and  sweet  during  storage,  or  the  actual  costs  will  be  raised  consid- 
erably. It  is  important,  therefore,  in  constructing  corn  cribs  to  take 
full  advantage  of  the  possibilities  of  natural  ventilation.  When  soft 
corn  is  stored,  it  is  usually  advisable  to  provide  additional  ventilating 
devices  to  assist  in  the  abundant  and  thoro  natural  circulation  of  air. 
Information  on  the  construction  and  auxiliary  ventilation  of  corn  cribs 
may  be  obtained  on  request  from  the  Farm  Mechanics  Department  of 
this  Station. 


1927]  COSTS  OF  STORING  CORN  15 

SUMMARY 

The  items  of  cost  and  of  profit  in  storing  corn,  outside  of  the 
chances  for  change  in  the  corn  price  level,  include  interest  on  the  money 
tied  up  in  the  corn,  interest  and  depreciation  charges  on  cribs  used, 
insurance  against  loss  from  fire  and  storms,  shrinkage,  and  change  in 
grade.  The  last  two  items  are  by  far  the  most  important. 

Since  corn  may  contain  anywhere  from  18  to  30  percent  or  more 
of  moisture  when  cribbed,  depending  on  the  maturity  of  the  crop  and 
on  weather  conditions,  it  is  inadvisable  to  figure  shrinkage  on  the  basis 
of  averages.  Well-matured  ear  corn,  gathered  late  in  the  season,  may 
be  expected  to  shrink  about  13  percent  from  the  time  it  is  cribbed 
until  the  following  summer.  Corn  which  is  not  so  well  matured  and 
hence  contains  more  moisture,  but  is  still  good  enough  to  keep  well 
under  proper  storage  conditions,  may  be  expected  to  shrink  as  much 
as  20  to  21  percent  during  the  same  period.  Corn  which  is  very  "soft" 
or  immature  will  of  course  shrink  even  more. 

The  problem  of  shrinkage  when  corn  is  sold  on  a  shelled  basis  is 
entirely  different  from  that  when  it  is  sold  on  the  ear.  The  cobs  shrink 
more  in  weight  than  the  kernels,  so  that  the  proportion  of  loss  of 
weight  is  less  for  the  kernels  than  for  the  entire  ear.  Therefore,  if  only 
the  weight  of  the  shelled  grain  enters  into  the  sale,  the  larger  propor- 
tional item  of  shrinkage  is  eliminated.  For  this  reason,  when  corn  is 
sold  on  a  shelled  basis,  the  shrinkage  to  be  allowed  for  is  reduced  to 
between  two-thirds  and  three-fourths  as  much  as  for  ear  corn. 

Because  the  moisture  content  of  ear  corn  is  lowered  during  storage, 
the  grade  will  usually  be  raised.  This  constitutes  a  factor  of  profit  in 
that  the  discount  on  the  lower  grade  is  avoided.  The  additional  return 
is  often  enough  to  offset  nearly  all  or  even  all  of  the  costs  of  storage. 

It  must  be  remembered,  however,  that  if  corn  goes  "out  of  condi- 
tion," or  is  otherwise  materially  damaged  during  storage,  the  grade 
will  not  be  raised  and  may  even  be  lowered.  If  the  grade  is  not  raised, 
the  corn  will  be  subjected  to  a  discount,  and  if  the  grade  is  actually 
lowered,  there  will  even  be  an  additional  loss. 


16 


BULLETIN  Xo.  295 


FIG.  2. — PLANT  FOR  GRAIN  DRYING  AND  SHRINKAGE  TESTS  AT  THE  ILLINOIS 

AGRICULTURAL  EXPERIMENT  STATION 

The  eight  cribs  are  mounted  on  wheels,  which  run  on  a  short  track  having 
a  scale  in  the  center.  Cribs  1  to  4  are  equipped  for  artificial  drying,  cribs  5  to  8 
depend  on  natural  ventilation,  and  9  is  the  scale  house,  containing  also  a  furnace 
and  blower  for  forcing  heated  air  thru  the  cribs.  Shed  10  is  a  blower  used  to  force 
unheated  air  in  a  similar  manner.  This  is  the  plant  referred  to  in  the  footnote 
on  page  5. 


UNIVERSITY  OF  ILLINOIS-URBANA 


